Barack Obama singles out Koch brothers over fossil fuel lobbying

US president says conservative politicians and businesspeople are 'standing in the way of the future' by opposing his clean energy measures

Barack Obama has railed against US political and business figures who oppose the expansion of wind and solar power in a speech where he singled out the influential Koch brothers for criticism.

Accusing opponents of his energy policies of "wanting to protect an outdated status quo" based on fossil fuels, he warned them away from "standing in the way of the future" and his efforts to combat climate change.